7 Best Non-Condensing Tankless Water Heaters, Compared

Quick picks

The best fit for you

• You need consistent indoor natural gas heating VancEpic 4.8 GPM Natural Gas Tankless Heater It delivers ±1°F temperature management and 110,000 BTU output for stable indoor performance.
• You want the most compact outdoor propane unit Rinnai 6.1 GPM Outdoor Propane Water Heater Its 10.8-inch length and 14.1-inch width make it the narrowest outdoor propane model listed.
• You require high indoor flow with smart control Rheem RTG 9.5 GPM Natural Gas Water Heater It pairs 9.5 GPM capacity with Wi-Fi connectivity for large indoor natural gas homes.
• You need maximum BTU output for high demand Westinghouse 10.3 GPM Natural Gas Tankless Heater It provides 199,000 BTU output to serve up to seven fixtures reliably indoors.
• You want outdoor propane with Wi-Fi control Rheem RTG 9.5 GPM Outdoor Propane Tankless Heater It offers 9.5 GPM flow and Wi-Fi features for exterior propane installations.

Our 7 picks

1 Best overall

VancEpic 4.8 GPM Natural Gas Tankless Heater

Best for: mid-sized homes using indoor natural gas

Venting Type

Non-Condensing (what this guide is about)

Fuel Type

Natural Gas

Flow Rate

4.8 GPM

BTU

110,000 BTU

Installation Location

Indoor

Temperature Control

±1°F

View on Amazon: VancEpic 4.8 GPM Natural Gas Tankless Heater

The VancEpic 4.8 GPM Indoor Natural Gas Tankless Heater provides on-demand hot water using a non-condensing design and 110,000 BTU output. It delivers up to 4.8 GPM flow, which supports three to five water outlets simultaneously. If you need an indoor natural gas unit with precise ±1°F temperature control and standard 1/2-inch NPT fittings for a mid-sized home, this model fits your space.

Pros

• Delivers up to 4.8 GPM and 110,000 BTU output
• Maintains water temperature within ±1°F with four preset modes
• Oxygen-free copper heat exchanger for efficient heat transfer
• Standard 1/2-inch NPT water and air inlet connections
• Includes freeze protection and child lock safety functions

Cons

• Flow rate tops out at 4.8 GPM, lower than 7.0+ GPM alternatives
• Warranty is limited to 2 years
• Requires indoor space and venting rather than outdoor mounting

Good fit if

• You need an indoor natural gas heater for 3 to 5 simultaneous fixtures.
• You want stable temperature output held within ±1°F.
• You have standard 1/2-inch NPT plumbing connections.

Skip if

• You require high flow rates above 4.8 GPM for larger households.
• You need a liquid propane or outdoor-rated water heater.
• You want a warranty term longer than 2 years.

Verdict: VancEpic 4.8 GPM Indoor Natural Gas Tankless Heater delivers consistent ±1°F temperature management and 110,000 BTU output for mid-demand homes. It provides an efficient indoor non-condensing solution when you do not need the higher flow rates of larger units.

2 Best budget

Rinnai 6.1 GPM Outdoor Propane Water Heater

Best for: outdoor propane installations serving multiple fixtures

Venting Type

Non-Condensing (what this guide is about)

Fuel Type

Propane

Flow Rate

6.1 GPM

BTU

160k BTU

Installation Location

Outdoor

Dimensions

24.6 x 14.1 x 10.8 in

View on Amazon: Rinnai 6.1 GPM Outdoor Propane Water Heater

This outdoor propane model delivers up to 6.1 GPM of hot water, which can run up to five fixtures at once. Because it mounts outdoors, you do not need to install indoor venting through your roof or walls. The cabinet measures 24.6 by 14.1 by 10.8 inches and weighs 49.2 pounds. It suits you if you run liquid propane and need an exterior setup.

Pros

• Delivers flow rate up to 6.1 GPM for up to five fixtures
• Outdoor installation eliminates indoor exhaust venting requirements
• LED display provides service reminders and error codes
• Compact exterior dimensions of 24.6 by 14.1 by 10.8 inches

Cons

• WiFi control module is not included
• Outdoor installation only with no indoor mounting support
• Labor warranty drops to 1 year without registration within 90 days

Good fit if

• You have an exterior mounting location and run liquid propane.
• You need flow rates reaching 6.1 GPM for multiple simultaneous fixtures.
• You want an onboard digital interface showing diagnostic codes.

Skip if

• You need an indoor water heater installation.
• You use a natural gas line rather than propane.
• You want built-in wireless connectivity without separate accessories.

Verdict: Rinnai 6.1 GPM Outdoor Propane Water Heater provides a dedicated outdoor propane heating setup with up to 6.1 GPM capacity. Its compact frame mounts externally and features an LED diagnostic display.

3 Best premium

Rheem RTG 9.5 GPM Natural Gas Water Heater

Best for: multi-bathroom homes needing high indoor flow

Venting Type

Non-Condensing (what this guide is about)

Fuel Type

Natural Gas

Flow Rate

9.5 GPM

BTU

199,900 BTU/hr

Installation Location

Indoor

Temperature Control

±1°F

View on Amazon: Rheem RTG 9.5 GPM Natural Gas Water Heater

This indoor non-condensing tankless water heater runs on natural gas, delivering up to 9.5 GPM at a 35°F temperature rise with a 199,900 BTU burner. It supports three to four simultaneous showers and connects via built-in Wi-Fi for monitoring. If you have a natural gas hookup and need high-volume hot water for a multi-bathroom household, this direct-vent unit provides precise temperature adjustments in single-degree increments.

Pros

• Delivers up to 9.5 GPM at 35°F temperature rise with 199,900 BTU burner
• Built-in Wi-Fi capability and digital LED display with ±1°F control
• 15-year heat exchanger warranty and 5-year parts warranty
• Equipped with freeze protection and flame failure protection

Cons

• Requires indoor direct vent system installation
• Professional installation required
• Configured strictly for natural gas rather than liquid propane

Good fit if

• You have a natural gas supply and need to supply 3 to 4 simultaneous showers.
• You want built-in Wi-Fi connectivity and single-degree digital temperature control.
• You need an indoor wall-mounted unit with dedicated venting hardware.

Skip if

• You require a liquid propane water heater.
• You plan to install the unit outdoors.

Verdict: Rheem RTG 9.5 GPM Natural Gas Indoor Tankless Heater pairs a high-output 199,900 BTU burner with Wi-Fi control for large homes using natural gas. It handles up to four simultaneous showers through an indoor direct-vent setup.

4 Best 199,000 btu

Westinghouse 10.3 GPM Natural Gas Tankless Heater

Best for: high-demand indoor households using natural gas

Venting Type

Non-Condensing (what this guide is about)

Fuel Type

Natural Gas

Flow Rate

10.3 GPM

BTU

199,000 BTU/hr

Installation Location

Indoor

Temperature Control

WiFi & APP control

View on Amazon: Westinghouse 10.3 GPM Natural Gas Tankless Heater

This indoor non-condensing water heater runs on natural gas and delivers up to 10.3 GPM with a 199,000 BTU maximum heat output. It features built-in Wi-Fi and mobile app temperature control, supplying hot water for up to seven fixtures simultaneously. You will find it suitable if your household demands high concurrent hot water flow indoors and you want mobile app adjustments without needing dedicated wall remotes or manual panel access.

Pros

• Delivers a 10.3 GPM flow rate
• High heat output of 199,000 BTU
• Built-in Wi-Fi and mobile app temperature control
• Rated capacity handles up to seven fixtures

Cons

• Designed only for indoor installation
• Configured solely for natural gas fuel
• Unit weighs 56 pounds

Good fit if

• You have an indoor natural gas hookup
• You need high capacity for up to seven simultaneous fixtures
• You prefer adjusting water temperature via a mobile app

Skip if

• You need an outdoor water heater installation
• You use liquid propane rather than natural gas

Verdict: Westinghouse 10.3 GPM Natural Gas Tankless Heater provides high 199,000 BTU output and smart connectivity for demanding indoor setups. It serves up to seven fixtures reliably using natural gas.

5 Also great

Rheem RTG 9.5 GPM Outdoor Natural Gas Tankless Heater

Best for: outdoor installations supporting multiple simultaneous showers

Venting Type

Non-Condensing (what this guide is about)

Fuel Type

Natural Gas

Flow Rate

9.5 GPM

BTU

199,900 BTU/hr

Installation Location

Outdoor

Temperature Control

±1°F

View on Amazon: Rheem RTG 9.5 GPM Outdoor Natural Gas Tankless Heater

This outdoor non-condensing water heater runs on natural gas and delivers up to 9.5 GPM with a 199,900 BTU input. Because you mount it outside, it requires no indoor exhaust venting. The unit features a 0.82 Uniform Energy Factor and a digital control panel with precise 1-degree temperature adjustments. It suits high-demand households running three to four simultaneous showers that have exterior mounting space.

Pros

• Delivers 9.5 GPM flow rate with 199,900 BTU/hr natural gas output
• Outdoor wall mounting eliminates the need for dedicated venting ducts
• Digital LED display allows precision adjustments of plus or minus 1°F
• Includes built-in freeze protection and flame failure safety systems

Cons

• Outdoor installation only and cannot be installed indoors
• This base 9.5 GPM configuration does not include WiFi capability
• Requires professional installation by a qualified technician

Good fit if

• You need hot-water volume to run three to four showers simultaneously.
• You prefer an exterior wall installation to skip indoor venting.
• You already have an outdoor natural gas supply line available.

Skip if

• You need an indoor-mounted tankless unit.
• You use liquid propane rather than natural gas.
• You require built-in WiFi connectivity out of the box.

Verdict: Rheem RTG 9.5 GPM Outdoor Natural Gas Tankless Heater delivers robust 199,900 BTU performance for high-demand homes without requiring indoor exhaust venting. It provides stable multi-bath flow backed by durable metal housing and a 15-year heat exchanger warranty.

6 Also great

Rheem RTG 9.5 GPM Outdoor Propane Tankless Heater

Best for: large homes needing outdoor propane water heating

Venting Type

Non-Condensing (what this guide is about)

Fuel Type

Liquid Propane

Flow Rate

9.5 GPM at 35°F rise

BTU

199,900 BTU/hr

Installation Location

Outdoor

Temperature Control

Digital LED, ±1°F

View on Amazon: Rheem RTG 9.5 GPM Outdoor Propane Tankless Heater

This outdoor liquid propane tankless water heater delivers up to 9.5 GPM at a 35°F temperature rise using 199,900 BTU/hr. Because you install it outdoors, it eliminates the need for indoor exhaust venting. It provides a 0.82 Uniform Energy Factor and includes digital LED temperature controls with 1°F adjustments. It suits high-demand homes running on liquid propane that have exterior mounting space.

Pros

• High 9.5 GPM flow rate at 35°F temperature rise
• 199,900 BTU/hr heating capacity
• Outdoor installation eliminates dedicated venting runs
• Precise digital LED temperature adjustments in 1°F increments

Cons

• Outdoor installation only
• Requires liquid propane supply instead of natural gas
• Non-WiFi configuration

Good fit if

• You use liquid propane and need up to 9.5 GPM for multiple fixtures.
• You have outdoor wall space and want to avoid installing indoor vent piping.
• You want precise temperature control down to 1°F increments.

Skip if

• You need an indoor water heater.
• You are connected to a natural gas line.
• You require wireless app connectivity out of the box.

Verdict: Rheem RTG 9.5 GPM Outdoor Propane Water Heater delivers high flow rates for propane-fueled homes without the complexity of indoor venting. Its 199,900 BTU/hr output provides whole-house capacity from an exterior wall mount.

7 Also great

Rheem RTG Series 7.0 GPM Propane Tankless Water Heater

Best for: indoor propane homes with 2-3 fixtures

Venting Type

Non-Condensing (what this guide is about)

Fuel Type

Liquid Propane

Flow Rate

7.0 GPM

BTU

160,000 BTU/hr

Installation Location

Indoor

Temperature Control

±1°F

View on Amazon: Rheem RTG Series 7.0 GPM Propane Tankless Water Heater

The Rheem RTG 7.0 GPM Indoor Propane Water Heater provides on-demand hot water using liquid propane fuel and a direct-vent non-condensing setup. It delivers up to 7.0 GPM at a 35°F rise using a 160,000 BTU burner and holds an energy rating of 0.82 UEF. If you need steady hot water for two to three simultaneous fixtures inside a propane-powered home, this compact wall-hung unit matches your capacity demands.

Pros

• Delivers 7.0 GPM at a 35°F rise with 160,000 BTU/hr input
• Energy efficiency rating of 0.82 Uniform Energy Factor
• Digital LED panel supports precise ±1°F temperature adjustments
• Includes a 15-year heat exchanger and 5-year parts warranty

Cons

• Lacks built-in WiFi connectivity included on larger capacity sizes
• Requires direct-vent indoor venting hardware

Good fit if

• You heat your home with liquid propane and need an indoor direct-vent unit.
• You run two to three fixtures simultaneously at standard temperature rises.

Skip if

• You require natural gas rather than liquid propane.
• You want integrated WiFi management without moving up to a larger model.

Verdict: Rheem RTG 7.0 GPM Indoor Propane Water Heater delivers 160,000 BTU/hr of non-condensing heating across two to three simultaneous fixtures. It provides consistent temperature control down to 1°F increments in a compact indoor footprint.

Specifications side by side

Is Non-Condensing Worth It?

Non-condensing units exhaust hot flue gases directly outside. This requires standard metal venting but allows indoor installation where condensing models cannot fit. You get simpler maintenance since there is no condensate pump or drain line to manage. These heaters suit mid-sized homes or outdoor setups. They offer reliable heat without the complexity of condensing technology, making them a practical choice for many households.

Worth it if

• You need an indoor unit where condensing venting is not feasible
• You prefer simpler maintenance without condensate drainage
• You want a compact outdoor heater for propane or gas

Skip it if

• You require maximum energy efficiency from heat recovery
• You live in an area requiring specific condensing codes
• You want the lowest possible operating costs regardless of complexity

How we selected non-condensing models

We identified these units by scanning Amazon listings for the specific Venting Type: Non-Condensing. We verified that each product explicitly states this feature in its title or feature list. This ensures every model on the list meets your venting requirements. We only include one size or variant from each product family to avoid redundancy.

The products are ordered by availability first. We then sort by the listing's overall rating weighted by the number of ratings. Finally, we consider how many of our guide's criteria each spec set meets. All details come directly from the published specifications. We do not handle or test these products physically.

How to Choose the Right Non-Condensing Heater

1. Match Fuel Type to Supply

   Check your home’s fuel source before buying. The VancEpic 4.8 GPM Natural Gas Tankless Heater requires a natural gas line, making it unsuitable for propane-only homes. If you have propane, look for models like the Rinnai 6.1 GPM Outdoor Propane Water Heater, which is built specifically for that fuel. Using the wrong fuel type can damage the unit or create safety hazards. Verify your existing connection matches the heater’s fuel specification to ensure safe and efficient operation from day one.

2. Select Installation Location

   Decide if the unit goes indoors or outdoors. Indoor models like the Rheem RTG 9.5 GPM Natural Gas Water Heater need proper venting through a wall or roof. Outdoor units, such as the Rheem RTG 9.5 GPM Outdoor Natural Gas Tankless Heater, are weather-resistant and save interior space. Choose indoor for colder climates where pipes need protection, or outdoor if you have exterior wall space and want to avoid indoor venting complexity. Your choice dictates the venting method and enclosure needs.

3. Calculate Required Flow Rate

   Estimate your peak water usage to pick the right flow rate. Small homes with one bathroom may only need 4.8 GPM, like the VancEpic model. Larger homes with multiple bathrooms often require 9.5 GPM or more, such as the Rheem RTG 9.5 GPM series. The Westinghouse 10.3 GPM Natural Gas Tankless Heater serves high-demand households with up to seven fixtures. Ensure the GPM rating meets your simultaneous shower and sink usage to avoid temperature drops during peak hours.

4. Check BTU Output Capacity

   Higher BTU ratings provide more heating power for larger homes. The Rheem RTG 9.5 GPM Natural Gas Water Heater offers 199,900 BTU, supporting high flow rates in large families. Smaller units like the VancEpic 4.8 GPM Natural Gas Tankless Heater deliver 110,000 BTU, which is sufficient for mid-sized homes. Match the BTU output to your water demand and inlet temperature. Higher output ensures consistent hot water even in colder climates where incoming water is significantly cooler.

5. Consider Smart Features

   Determine if Wi-Fi control is necessary for your setup. The Rheem RTG 9.5 GPM Natural Gas Water Heater includes Wi-Fi for remote monitoring and adjustments. The Westinghouse 10.3 GPM Natural Gas Tankless Heater also offers smart connectivity for demanding indoor setups. If you prefer manual control, models like the Rinnai 6.1 GPM Outdoor Propane Water Heater focus on core heating performance without digital extras. Evaluate whether remote diagnostics and scheduling fit your lifestyle before prioritizing this spec.

Frequently asked questions

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